Refrigerating appliance comprising a no-frost system

ABSTRACT

A refrigerating appliance having at least one storage compartment cooled by circulating air; a mobile control element to control at least one circulation condition of the circulating air in the storage compartment; a motor to adjust the mobile control element; a control unit to adjust, by means of the motor, a position of the mobile control element according to a circulation condition value that is specified by a user; and a data memory; wherein at least one assignment value is stored in the data memory that assigns the circulation condition value suitable for at least one type of cooled item.

The present invention relates to a refrigerating appliance comprising an evaporator and at least one compartment cooled by circulating air from and to the evaporator. In a refrigerating appliance of this type known from DE 10 2005 021 560 A1 a distribution chamber is formed adjacent to the cooling compartment which is separated from said compartment by a perforated wall. The holes can be covered on the distribution chamber side by a fleece in order to prevent a strong stream of cold air from the distribution chamber hitting sensitive cooled items in the compartment and drying them out. The airflow slowed down by the diffusion layer can however result in condensation water only being removed inadequately from the compartment. Thus cooled items in the compartment can become damp, which is also not desirable.

The correlation between the amount of moisture in the compartment and whether or not the holes are covered by the fleece is not immediately obvious to a user because the amount of moisture that the user observes in the compartment is primarily a function of the type of cooled items stored in said compartment. It is therefore highly probable that a user will not handle the fleece correctly and will not set appropriate storage conditions for the cooled items in question.

The object of the present invention is to further develop the known refrigerating appliance in such a way that the probability of incorrect use is reduced.

The object is achieved by the features claimed in claim 1: As the user can directly specify the desired circulation condition, in particular the degree to which moisture is removed from the content of the compartment, the user does not need to know the correlation between the position of the control element and the circulation conditions that result from it. In such cases what is specified by the user is usually based on an empirically calculated value stored in a data memory, although the user can if necessary also change this value and transfer the changed value to another data memory or, alternatively, overwrite the specified value with the changed value.

According to a first, simple embodiment the control unit is set up to ascertain the specified value by offering the user various values relating to the circulation condition from which to choose.

According to a more developed embodiment, which can be combined with the first embodiment in an appliance in various operating modes, the control unit is set up to ascertain the specified value by offering various types of cooled item possibly accommodated in the storage compartment from which to choose and selecting a suitable value relating to the circulation condition for the specified cooled item on the basis of the user input specifying the type of cooled item.

In order that the correct choice of circulation condition can be made it is preferable that an assignment table be stored in the control unit that assigns suitable values relating to the circulation condition in each case for a quantity of types of cooled item.

As various types of cooled item can be accommodated in the storage compartment simultaneously, the control unit ought to be able to react appropriately to the input of a user who specifies various types of cooled item. If the circulation condition is a quantitative amount, i.e. can be expressed in numbers that give a smaller/larger ratio, it is preferable for the control unit to be set up to select a value relating to the circulation condition to be adjusted at the control element that is at least as great as the lowest value assigned to a specified type of cooled item and is not greater than the highest value assigned to a specified type of cooled item.

A rule for selecting the adjustable value of the circulation condition when several types of cooled item are input can be specifiable by the user.

The following can be considered as possible rules:

a. Select the respective lowest value assigned to a specified type of cooled item, b. Select the respective highest value assigned to a specified type of cooled item, c. Form a mean value from among the values assigned to the specified types of cooled item.

The refrigerating appliance can comprise a circulation path for circulating air from an evaporator to the storage compartment that passes through a diffusion layer, as well as a circulation path that bypasses the diffusion layer. In this case an element is expediently provided as a control element in such a position as to influence the distribution of the circulating air to the two circulation paths.

In particular, air passage openings can be formed in a wall separating an air flow area from the compartment, and a diffusion layer can be moved, by means of the motor, between a first position in which it covers the air passage openings and a second position in which it enables air to stream through the air passage openings while bypassing the diffusion layer.

In the second position the diffusion layer in particular can be offset from the dividing wall.

Further features and advantages of the invention emerge from the description given below of exemplary embodiments which refer to the enclosed figures. The figures show

FIG. 1 a perspective view of a refrigerating appliance according to the invention;

FIG. 2 a section through the refrigerating appliance shown in FIG. 1 along the line II from FIG. 1;

FIG. 3 a perspective view of the wall separating the compartment and the distribution chamber and of items installed on it;

FIG. 4 a perspective view of a control disk;

FIG. 5 a section through the control disk and its environment;

FIG. 6 an overhead view of a wall separating the distribution chamber and the compartment seen from the distribution chamber, in accordance with a second embodiment of the invention;

FIG. 7 a section through the wall shown in FIG. 6; and

FIG. 8 a flow diagram of a process for controlling the circulation of air through the distribution chamber.

FIG. 1 shows a perspective view at an angle from below of a refrigerating appliance with reference to which the present invention is to be explained. The device has a carcass 1 and a door 2 closing onto it. The inside of the carcass 1 is divided into an evaporator area 3 at the top below the roof of the carcass 1, a first cooling area 4 and, separated from this by an insulating dividing wall 5, a second cooling area 6. The second cooling area 6 is divided into two compartments by pull-out drawers 7 arranged next to one another. The first cooling area 4 is normally divided by a number of cooled item carriers into compartments resting on top of one another. These cooled item carriers are omitted in FIG. 1 as they are not of significance for the current invention.

Formed on the front side of a dividing wall 9 separating the evaporator area 3 from the first cooling area 4 (see FIG. 2) is an air inlet opening 10 through which air can enter from the first cooling area 4 into the evaporator area 3. Lines through which air can flow from the second cooling area 6 to the evaporator area 3 can—not visible in FIG. 1—run in the side walls of the carcass 1; another option indicated in FIG. 1 is an air line 11 in the inside of the door 2 which begins at the height of the second cooling area 6 and ends opposite the air inlet opening 10, and the course of which is shown in the figure by dashed lines.

Attached on the dividing wall 9 adjacent to the rear wall 8 of the carcass 1 is a distribution cowl 12 on which a plurality of air holes 13 is formed, through which the cooling air coming from the evaporator area 3 is distributed in the upper part of the first cooling area 4 in various directions. Located on the rear wall 8 below the distribution cowl 12 are several pairs of openings 14 out of which cooling air can also flow. The height of these pairs of openings 14 is selected so that when cooled item carriers are installed in the first cooling area 4, each pair of openings 14 supplies a compartment delimited by the cooled item carriers.

FIG. 2 shows the refrigerating appliance shown in FIG. 1 in a section along a plane extending vertically and in the downwards direction of the carcass 1, which is represented in FIG. 1 by a dotted and dashed line II. Cooling loops of an evaporator 15 are to be seen inside the evaporator area 3 in the sectional view against which the air penetrating through the air inlet opening 10 flows. The dividing wall 9 slopes down in relation to the rear wall of the carcass 1 into a channel 16 in which condensation water dripping off the evaporator 15 collects. The condensation water reaches a condenser housed in the base area 17 (see FIG. 1) of the carcass 1 via a pipe not shown in the diagram.

Accommodated behind the channel 16, adjacent to the rear wall 8, is a fan which comprises a motor 18, a blade wheel 19 driven by said motor and a housing 20. On the front side of the housing 20, in the axial direction of the blade wheel 19, is formed an induction opening. The upper half of the housing 20 runs in the circumferential direction closely around the blade wheel 19; the housing 20 is open at the bottom so that a rotation of the blade wheel 19 causes air accelerated radially outwards to flow down into a chamber 21.

Accommodated in this chamber 21 is a swivel-mounted flap 22. In the position shown in the figure the flap 22 blocks a cold air supply opening 23 which leads vertically downwards to the first cooling area 4. This means that the air is forced out towards the rear wall 8 and into a cold air supply path 24 which leads within the rear wall 8 from the first cooling area 4, separated by a thin insulation layer 25, to the second cooling area 6. If the flap 22 swivel-mounted on a dividing wall 26 between the cold air supply opening 23 and the cold air supply line 24 is put into a vertical position, shown in the figure as a dotted outline, it blocks the cold air supply path 24 and the cold air flow reaches the distribution cowl 12 through the cold air supply opening 23. One of the air holes 13 through which the air flows out from the distribution cowl 12 into the first cooling area 4 can be seen in the section depicted in FIG. 2.

The cold air supply path 24 leads to a distribution chamber 27 which extends into the dividing wall 5 separated from the first cooling area 4 by an insulation layer above the second cooling area 6. Arranged between the distribution chamber 27 and the second cooling area 6 is a horizontal partition wall 29. It is provided with a plurality of openings 30 (see FIG. 3) via which the distribution chamber 27 distributes cooled air supplied via the supply path 24 and an air inlet opening 37 formed on the narrow side of the distribution chamber 27 over a large area into the cooling area 6 or the pull-out compartments 7 that are open at the top and accommodated within it.

From the cooling area 6, air flows via the air line 11 formed in the door 2 back to the evaporator area 3. To prevent an uncontrolled transfer of air between the cooling areas 4, 6 at different temperatures, the dividing wall 5 has a sealing profile 34 on its leading edge abutting the door 2.

The partition wall 29 can be installed in the carcass 1 so that it can be removed, for example as shown in FIG. 2, by resting it on bars 35 projecting from the side walls of the carcass 1. Thus, if the partition wall 29 is removed, the volume of the distribution chamber 27 can also be used, if necessary, to store cooled items.

FIG. 3 shows a perspective view of the partition wall 29 seen from the direction of the distribution chamber 27. Vertical bars 38 projecting from the partition wall 29 divide the distribution chamber 27 into two part chambers 27 a, 27 b, one of which is located above one of the two pullout drawers 7 and the other above the other pull-out drawer 7. In the right-hand part chamber 27 b a plate 40 b with multiple perforations is shown lying flat on the partition wall 29. Openings 31 of the plate 40 b coincide with the openings 30 of the partition wall 29 located below them in each case so that the plate 40 b does not impede the air flow from the part chamber 27 b into the pull-out drawer 7 below it.

Each of the plates 40 a, 40 b is intended to carry an air-permeable fleece 50 not shown in FIG. 3 lying flat on top of it (see FIG. 2) and covering all the openings 31 of the plates 40 a, 40 b. In the position shown for the plate 40 b, the fleece 50 assures an even distribution of the air to the openings 30 of the partition wall 29 and a slow, even flow of air which has a cooling effect in the compartment, or pull-out drawer 7, located below it, but still only has a slight drying effect.

Each of the plates 40 a, 40 b is suspended at its edge facing towards the rear wall 8 or the air inlet opening 37 from a free end of a two-arm pivot lever 41 a, 41 b. Controlled by a control unit 42 that can be rotary-driven by an electric motor 39 and is shown in greater detail in conjunction with FIG. 4, the pivot arms 41 a, 41 b are able to be pivoted around an axis which runs approximately at the height of the door-side edges of the plates 40 a, 40 b and parallel to these edges. If an opposing free end of one of the pivot levers 41 is pressed down by the control unit 42, as shown in the figure, using the left-hand pivot arm 41 a as an example, this lifts the associated plate, in this case the plate 40 a, at its edge adjacent to the air inlet opening 37, so that air flows from the air inlet opening 37 into an intermediate space narrowing in the shape of a wedge in relation to the door between the plate 40 a and the partition wall 29 and flows through the openings 30 of the partition wall 29 into the pull-out drawer 7 located below it. Since in this case the air flow is not attenuated by the fleece 50, the flow speed within the pull-out drawer 7 located below is higher than when the plate is lowered, so that the air supplied has a significantly greater drying-out effect in the pull-out drawer 7.

Two sensors 54 are provided to record the position—raised from or resting on the dividing wall 29—of the edges of the plates 40 a, 40 b facing towards the rear wall and to relay said position to a control circuit 56 (see FIG. 2) on the electric motor 39. FIG. 3 shows the sensors 54 as elements separated from the partition wall 29, e.g. elements built into the rear wall 8 of the carcass 1 of the refrigerating appliance that record the position of the plates 40, 40 b through the air inlet opening 37.

FIG. 4 shows a perspective view of the underside of the control element 42 hidden from view in FIG. 3. The control element 42 comprises a circular base plate 43 from which a non-round bushing 44 projects that is intended to accept the shaft of an electric motor 39 not shown in the diagram, hidden below the control element 2 in FIG. 3 (see FIG. 2 or FIG. 5). Arranged concentric to the bushing 44 at different radiuses are two ramps 45 a, 45 b. Each of these ramps 45 a, 45 b is intended to interact with one of the two pivot levers 41 a, 41 b engaging under the base plate. The two ramps 45 a, 45 b each have a gently rising flank 46, a top section 47 of constant height and a sharply falling flank 48. As can be seen in the cross section shown in FIG. 5, each of the pivot levers 41 a, 41 has, at its free end and interacting with the control element 42, an upright pin 49 that enables one of the pivot levers, the left-hand lever 41 a in the diagram in FIG. 5, to scan the control element 42 on the radius of the inner ramp 45 a without coming into contact with the outer ramp 45 b in doing so.

The result of the two ramps 45 a, 45 b being suitably offset from each other at an angle is that there is a position of the control element 42 in each case in which the pins 49 of the two pivot levers 41 a, 41 b touch the base plate 43, a position in which one pin 49 touches the top section 47 of the ramp 45 a while the other pin 49 touches the base plate, a position in which both pins 49 touch the top section 47 of the ramp 45 a or 45 b assigned to them, as well as a position in which one pin 49 touches the top section of the ramp 45 b while the other touches the base plate 43. Expediently the positions follow each other in the stated sequence during a rotation of the control element 42. The direction of rotation of the motor 39 is selected so that the pins 49 glide in each case along the gently rising flanks 46 to the top section 47 and subsequently fall back along the steep flanks 48 to the base plate 43. The fact that the flanks 48 are kept steep means that on the one hand the angle intervals at which one of the four positions is present can be made large so that only a small degree of precision is required in the control of the angle of rotation of the control element 42, whereas on the other hand the gentle rise of the flanks 46 makes it easier for the pins 49 to slide onto the ramps 45 a, 45 b and facilitates the associated lifting of the plates 40.

A second embodiment of the partition wall 29 and of parts mounted on it is shown in an overhead view in FIG. 6 and in FIG. 7 in a section along the line VII-VII in FIG. 6. As in the embodiment shown in FIGS. 3 to 5, the partition wall has a plurality of air passage openings 30 and a plate 40 a or 40 b bearing a fleece 50 (see FIG. 6) can, as shown in FIG. 6 by the example of the left-hand plate 40 a, assume a position in which it is lying flat on the partition wall 29 in which the openings 31 of the plate 40 a are aligned with those of the partition wall 29. Ramps 53 are formed on bars 38 extending in the downwards direction of the carcass 1 and rising towards the rear wall 8. In the case of the left-hand plate 40 a, pins 51 projecting from the plates 40 a, 40 b are in each case located at the foot of the ramps 53.

Rotatable control elements 42 coupled, for example, by an electric motor not shown in the diagram, each comprise a base plate 43 and an eccentric projection raised from it, here in the form of a circle sector-shaped rib 52. If the rotation of the control element 42 causes the rib 52 to press against the plate 40 a or 40 b, as shown by the example of the right-hand plate 40 b in FIG. 6, the latter is pushed backwards in the direction of the air inlet opening 37, it being possible for the pins 51 to slide up onto the ramps 53 and in so doing lift the plate 40. A space is thus produced between the plate 40 and the partition wall 29 through which air can travel from the air inlet opening 37 directly to the openings 30 of the partition wall 29, without its flow being attenuated by the fleece 50. The effects obtained in this way are the same as for the embodiment described above.

The fact that the ribs 52 of the control element 42 are set at a suitable angle to each other means that four states can also be set here, in which either the two plates 40 a, 40 b rest on the partition wall 29, one plate rests on the wall in each case and the other is raised, or both plates 40 are raised.

By contrast with the diagrams shown in FIGS. 6 and 7, it is also possible to omit the ramp adjacent to the door 2 in each case, i.e. the upper ramp shown in the diagram in FIG. 6 or the left-hand ramp 45 shown in the diagram in FIG. 7, from the ramps 53. This results in each of the plates 40 a, 40 b being able to be moved between the position shown in FIG. 7 resting on the partition wall 29 and an offset position, in which in each case only the edge of a plate 40 a, 40 b adjacent to the air inlet opening 37 is lifted away from the partition wall 29, whereas the edge of the plate close to the door continues to rest on the wall. Thus, as shown in the embodiment in FIG. 3, in the offset position a wedge-shaped intermediate area, which drives the air flowing in from the air inlet opening 37 toward the partition wall 29, is formed in each case between plate 40 and partition wall 29.

Diverse variations and developments of the exemplary embodiments described here are possible. Thus, for example, the rotatable control elements 42 can be replaced by linearly displaceable ramps, or other drive mechanisms for moving the plates 40 a, 40 b can be provided.

In order that the position of the plates 40 a, 40 b can be adjusted to the cooled items stored in the assigned pull-out drawer 7 at any time, a user interface 55 is provided at which a user—by selecting from a displayed menu, for example—can specify the type of cooled item stored in each pull-out drawer and, on the basis of an assignment table, an electronic control circuit 56 selects and sets the position of the plates 40 a, 40 b that is appropriate to the respective cooled items.

FIG. 8 shows a flow diagram of a control process that takes place in the control circuit 56 of the electric motor 39. In a first step S1 a user is given the opportunity, at the user interface 55, to input the type or types of cooled item stored in the compartments 7. FIG. 1 shows this user interface with a display screen and multiple buttons, option selectors or similar on the leading edge of a cover plate of the carcass 1; it can, of course, be incorporated in any other suitable place. User input can, for example, be as a result of a user selecting, by means of the buttons or option selectors and for one of the compartments 7 in each case, from among the pictograms or identifiers of various kinds of cooled items displayed on the display screen, the item or items that he or she has stored in the compartment 7 in question.

In step S2 the control circuit 56 specifies a default position for the plate 40 a or 40 b corresponding to the compartment on the basis of the content indicated for each compartment 7. This is done by consulting a table 56 stored in the control circuit that gives a default plate position for every type of cooled item offered to the user to choose from in step S1. In the simplest case this default position either has the value 0 or the value 1, depending on whether the plate is lying flat or is fully raised. Intermediate values for the position of the plate can however also be given in the table.

If the user has only specified one type of cooled item for a compartment 7, the default position specified for the compartment corresponds to the position given in the table for that cooled item. If various types of cooled item are specified, as a default position for the compartment a mean value for the default values that apply to the types of cooled item contained therein can be the highest or the lowest of these default values. Which of these three alternatives is chosen can depend on the type of cooled item specified. If, for example, loose leafy vegetables are specified, the default value for this item is then most likely to be selected as the default plate position, as this cooled item becomes damaged more rapidly when conditions become very dry, whereas for other types of cooled item a mean value is calculated. In each case, two numerical values in the interval of [0.1], one for each compartment 7, are obtained as the default position.

In step S3 the default positions obtained in this way are compared with a circuit threshold. In the simplest case the circuit threshold can be a constant, e.g. 0.5. If the default position is above this, a decision is made to raise the relevant plate; if it is below it, the plate should be lowered. If the sensors 54 report that both plates 40 a, 40 b are already in the default position calculated for them

then the motor 39 remains switched off and the process transfers to step S4, in which the fan is

operated in order to circulate cold air between the evaporator area 3 and the cooling area 6.

If both plates 40 a, 40 b are not in the default position the control circuit sets the motor 39 running until either the sensors 54 in step S5 report that the default position has been reached or until it is ascertained in step S6 that a maximum permitted running time of the motor 39 has been exceeded. If the latter is the case, a malfunction is present, for example because one of the plates 40 a, 40 b is frozen solid to the partition wall 29 and as a result the control unit 42 is prevented from rotating and the malfunction is indicated to the user on the display screen of the user interface 55.

According to a more developed embodiment, step S3 is also periodically repeated by the control circuit 56 in step S4 after the fan starts operating, as indicated in FIG. 8 by a dashed arrow, the circuit threshold is not a constant but a saw tooth-shaped function of time varying between 0 and 1 and the control circuit 56 decides that the plate 40 a or 40 b is to be raised if its default position is lower than the circuit threshold and lowered if its default position is higher than the circuit threshold. Thus, while the fan is in operation the position of the plates 40, 40 b is periodically changed and the portion of time that they spend in the raised position is proportional to the running time of the fan in relation to the default position specified for them in step S2. 

1-12. (canceled)
 13. A refrigerating appliance, comprising: at least one storage compartment cooled by circulating air; a mobile control element to control at least one circulation condition of the circulating air in the storage compartment; a motor to adjust the mobile control element; a control unit to adjust, by means of the motor, a position of the mobile control element according to a circulation condition value that is specified by a user; and a data memory; wherein at least one assignment value is stored in the data memory that assigns the circulation condition value suitable for at least one type of cooled item.
 14. The refrigerating appliance of claim 13, wherein the data memory is arranged in the control unit; wherein the data memory stores an assignment table that assigns a respective circulation condition value that is suitable for a set of types of cooled item.
 15. The refrigerating appliance of claim 14, wherein the circulation condition is a quantitative variable; wherein the control unit selects the circulation condition value be adjusted at the mobile control element based on a user input specifying a plurality of types of cooled items; wherein the circulation condition value is at least as great as the lowest value assigned to a specified type of cooled items; and wherein the circulation condition value is not greater than the highest value assigned to the specified type of cooled items.
 16. The refrigerating appliance of claim 15, wherein a rule is selected from among at least two of: selecting a respective lowest value assigned to the specified type of cooled items; selecting a respective highest value assigned to the specified type of cooled items; and forming a mean value from among at least one of the respective lowest value and the respective highest value assigned to the specified type of cooled items.
 17. The refrigerating appliance of claim 16, wherein the rule is selected by the user.
 18. The refrigerating appliance of claim 16, wherein the control unit is structured to select the rule based on the specified type of cooled items.
 19. The refrigerating appliance of claim 13, wherein the control unit ascertains the circulation condition value by offering the user a plurality of circulation condition values from which to choose.
 20. The refrigerating appliance of claim 13, wherein the control unit ascertains the circulation condition value by offering a plurality of types of cooled items accommodated in the storage compartment from which to choose and by selecting a suitable circulation condition value for a specified cooled item based on a user input specifying a type of cooled item.
 21. The refrigerating appliance of claim 13, wherein the circulation condition is a degree of moisture of the circulating air.
 22. The refrigerating appliance of claim 13, further comprising a first circulation path for circulating air from an evaporator to the storage compartment that passes through a diffusion layer and a second circulation path that bypasses the diffusion layer, and wherein the position of the mobile control element influences distribution of the circulating air to the first and second circulation paths.
 23. The refrigerating appliance of claim 13, wherein air passage openings are formed in a wall separating an air flow area from the storage compartment; wherein a diffusion layer is moved, by means of the motor, between a first position in which the diffusion layer covers the air passage openings and a second position in which the diffusion layer enables air to stream through the air passage openings while bypassing the diffusion layer.
 24. The refrigerating appliance of claim 23, wherein, when the diffusion layer is in the second position, the diffusion layer is at a predetermined distance from the wall. 